Unfortunate.

Back in June, the founder of 4G hotspot provider Karma got up on stage and announced partnerships with American Airlines and car service Uber. Only there were no final, formalized partnerships–just “talks” that might’ve been going well, but certainly weren’t done. At the time, it looked like a pretty devastating misstep.

Fast forward to Wednesday, when one of the world’s largest tech companies did some similar fudging. Google announced “a new, cloud-based version of the Google Wallet app that supports all credit and debit cards from Visa, MasterCard, American Express, and Discover. Now, you can use any card when you shop in-store or online with Google Wallet.” Pretty sweet for those of you racking up the AmEx rewards.

Only, there’s a little detail that Google omitted. TechCrunch reports that while it’s true that you can load your card number into the app, American Express hasn’t exactly given that functionality the official a-okay. A representative told TechCrunch:

“We want to make sure Google’s mobile wallet product meets the standards we set for our Cardmembers in terms of transparency and clarity about transaction detail,” AmEx social media VP Bradley Minor told me. “Right now, American Express does not have an agreement with Google for our cards to be used in the Google mobile wallet.”

Also, if they choose, says TechCrunch, they could probably block the functionality. So sure, the Wallet works like Google says it does. But it’s not quite as official looking as you might assume from that blog post. No wonder it’s just MasterCard and Discover appearing in the snazzy sample images!

TechCrunch explains wherein lies the rub, as far as American Express is concerned:

As it stands, in-store Wallet transactions are actually handled by a virtual MasterCard PayPass account locked up in the device’s secure storage area, and those transactions are subsequently passed along to whatever credit card account the user had actually selected. Not all of the pertinent purchase information (like the specific merchants the purchase was made it) is carried over along with purchase amount though, and American Express doesn’t like that.

In response to the accusation, Google told TechCrunch:

“For many years, we’ve accepted American Express, Visa, MasterCard and Discover for online and mobile transactions. The latest version of Google Wallet extends these same benefits to people who choose to use the Google Wallet app to make purchases in-store. We are in active discussions with American Express and look forward to working together as partners as the world embraces digital payments.”

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